Dipicolinic acid contents used for estimating the number of spores in raw milk
A new rapid detection the number of spores method had been developed in raw milk through analyzing dipicolinic acid. The method was based on the concentration of DP A in raw milk which was converted into endospore numbers using endospore forming pure cultures as standards. To increase the detection limit the extraction of DPA from endospores in raw milk was optimized. The results showed adding 0.5 mL of the 0.1 mol L-1 DTT solutions into centrifuged raw milk (4 mL containing spores) and incubating at 25℃ for 30 min, then adding 2 mol L-1 HC1 at boiling water for 30 min, the concentration of DPA was highest. The relationship between the absorbency (expressed in DPA) and the counts of spores was established. And the regression equation was obtained that is y=0.1087 x-0.3182, R2=0.7842. Thus, the methods of detection spores were ascertained in skim milk. The detection limits were 1.46×103 CFU mL-1.
Xue Han Lanwei Zhang Zhen Feng Huaxi Yi Ming Du Lili Zhang Yanhua Li Weijun Wang
School of Food Science and Engineering, Harbin Institute of Technology, Harbin, 150090, China School of Food Science, Northeast Agricultural University, Harbin, 150030, China
国际会议
哈尔滨
英文
1467-1471
2011-03-26（万方平台首次上网日期，不代表论文的发表时间）